Code 41, no 02 detected on right side

[darmstro]

I just pulled the codes on my 91 sport and got a code 41, no heated oxygen sensor switch detected, right side, according to the Haynes manual.

First question, does this mean I need to replace that 02 sensor? Secondly, where do I find this sensor? And lastly, Does "right side" indicate passenger or driver side?

I did a search and couldn't find these specifics, any help would be appreciated.

Thanks

 

[MrShorty]

For the sake of education, the industry standard for "right" side means passenger side. In this case, however, it doesn't matter, since you only have one oxygen sensor between the cat and the junction of the Y-pipe.
Was the code 41 a KOER or a continuous memory code? I've seen people (myself included) get a "false" code 41 by running the KOER test with the engine cold. Was the 41 the only code present?
A code 41 could be caused by a bad O2 sensor, yes. However, there are other possible causes. It seems that most people's (including shops I've dealt with) strategy when dealing with an O2 sensor code is to replace the O2 sensor so they know the sensor is good, then check the other causes if the problem continues. If you like that strategy, then go for it. One thing I would suggest before replacing the sensor: Check the wiring to make sure all the connections are good and there are no breaks. Also, the circuit (aka "pinpoint) tests for a code 41 always have you check the fuel pressure, since incorrect fuel pressure can cause the engine to run lean.

 

[darmstro]

I was just about to reply to my own thread about the one sensor thing, never thought to actually look under the truck to find out. the code was a continuous memory, KOEO code.

I'd rather not replace the sensor if I don't have to, I just don't have any experience with this stuff so I'm not sure what to look for (I didn't even know what an o2 sensor was 'till this morning).

The CEL only comes on when the truck warms up, if that has any signifigance to narrowing down the problem, and I suppose I'll have to clear the codes since it's a continuous memory thing?

 

[dogfriend]

Originally posted by darmstro
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The CEL only comes on when the truck warms up, if that has any signifigance to narrowing down the problem, and I suppose I'll have to clear the codes since it's a continuous memory thing?

The reason the code only comes on after the truck is warmed up is because the O2 sensor(s) only work when hot - the engine control system goes into "closed loop" when the O2 sensors start to give a signal. It is most likely to be the O2 sensor causing the code, but there are other possibilities.

Check out this thread also. The PO0133 (OBD 2) code is somewhat analogous to the 41 code (early EEC-IV). O2 = HO2S

CEL Oxygen Sensor